The Guardian disclosed that the woman, known only as “Jessica”, is taking legal action against the police, alleging that Coles groomed and manipulated her.

In a statement on Monday, Coles said: “There have been news reports over the weekend about which I am unable to comment. This coverage is significantly impacting on my ability to carry out my duties as deputy police and crime commissioner.

He had pretended to be “Andy Davey”, a removal van driver living in a south London bedsit. Richard Coles described in his autobiography how his brother had “looked like he had just walked out of the woods, his hair long and shaggy, with a straggly beard, his ears rattling with piercings”.

Jessica has told how she met “Davey” in 1992 after she had joined the animal rights movement as a “naive, idealistic, unsophisticated and a very young 19”.

She said he became her first boyfriend and alleged that during their relationship of more than a year he concealed from her his real job as a police officer and his marriage to another woman.

She has said that she would not have consented to the relationship if she had known he was a police spy. At the time he was 32, although she says she thought he was about 24.

She has said: “Although not legally underage, I feel that my youth and vulnerability were used to target me. I was groomed by someone much older, and far more experienced, and I was manipulated into having a sexual relationship with him. I didn’t even know his real name.”